Tests with 4096-byte sector size confirm that it is
safe to use O_DIRECT with page_compressed tables.
That had been disabled on Linux, in an attempt to fix MDEV-21584
which had been filed for the O_DIRECT problems earlier.

The fil_node_t::block_size was being set mostly correctly until
commit 10dd290b (MDEV-17380)
introduced a regression in MariaDB Server 10.4.4.

fil_node_open_file(): Only avoid setting O_DIRECT on
ROW_FORMAT=COMPRESSED tables that use KEY_BLOCK_SIZE=1 or 2
(1024 or 2048 bytes).

fil_ibd_create(): Avoid setting O_DIRECT on ROW_FORMAT=COMPRESSED tables
that use KEY_BLOCK_SIZE=1 or 2 (1024 or 2048 bytes).

fil_node_t::find_metadata(): Require fstat() to be always invoked
outside Microsoft Windows, so that fil_node_t::block_size can be set.

fil_node_t::read_page0(): Rely on find_metadata() to assign block_size.

Thanks to Vladislav Vaintroub for testing this on Microsoft Windows
using an old-fashioned rotational hard disk with 4KiB sector size.

Reviewed by: Vladislav Vaintroub

This is a port of commit 00f620b2
and commit 6505662c from 10.2.

Before MDEV-14638, there was no race condition between the
execution of fetch_data_into_cache() and transaction commit.

fetch_data_into_cache(): Acquire trx_t::mutex before checking
trx_t::state, to prevent a concurrent transition from
TRX_STATE_COMMITTED_IN_MEMORY to TRX_STATE_NOT_STARTED
in trx_commit_in_memory().

ha_innobase::info_low(): While collecting statistics for
ANALYZE TABLE, ensure that dict_stats_process_entry_from_recalc_pool()
is not executing on the same table.

We observed result differences for the test innodb.innodb_stats because
dict_stats_empty_index() was being invoked by the background statistics
calculation while ha_innobase::analyze() was executing
dict_stats_analyze_index_level().

Tests with 4096-byte sector size confirm that it is
safe to use O_DIRECT with page_compressed tables.
That had been disabled on Linux, in an attempt to fix MDEV-21584
which had been filed for the O_DIRECT problems earlier.

The fil_node_t::block_size was being set mostly correctly until
commit 10dd290b (MDEV-17380)
introduced a regression in MariaDB Server 10.4.4.

fil_node_t::read_page0(): Initialize fil_node_t::block_size.
This will probably make similar code in fil_space_extend_must_retry()
redundant, but we play it safe and will not remove that code.

Thanks to Vladislav Vaintroub for testing this on Microsoft Windows
using an old-fashioned rotational hard disk with 4KiB sector size.

Reviewed by: Vladislav Vaintroub

This patch implements OS_DATA_FILE_NO_O_DIRECT on Windows.

This had been originally added in
mysql/mysql-server@192bb153b675fe09037a53e456a79eee7211e3a7
with the motivation to disable O_DIRECT for the dedicated tablespace
for temporary tables. In MariaDB Server,
commit 5eb53955 (MDEV-12227)
should be a better solution.

The code became orphaned later in
mysql/mysql-server@c61244c0e6c58727cffebfb312ac415a463fa0fe
and it had been applied to MariaDB Server 10.2.2 in
commit 2e814d47 and
commit fec844ac.

Thanks to Vladislav Vaintroub for spotting this.

MDEV-24916 : Assertion `current_stmt_binlog_format == BINLOG_FORMAT_STMT || current_stmt_binlog_format == BINLOG_FORMAT_ROW' failed in THD::is_current_stmt_binlog_format_row

Store old value of binlog format before wsrep code so that
if we bail out because wsrep is not ready for connections
we can restore binlog format correctly.

MDEV-18874 : Galera test MW-286 causes Mutex = TTASEventMutex<GenericPolicy>]: Assertion `!is_owned()' failed. assertion

MDEV-24649 galera.galera_bf_lock_wait MTR failed with sigabrt: Assertion `!is_ow
ned()' failed in sync0policy.ic on MutexDebug with Mutex = TTASEventMutex<GenericPolicy>

Bug was fixed as part of MDEV-23328, this just adds test cases to
regression set.

As evidenced by converstation on Zulip,
knowing where to install a plugin is important too.

Add missing dbug sync point and correct the test case.

MDEV-24916 : Assertion `current_stmt_binlog_format == BINLOG_FORMAT_STMT || current_stmt_binlog_format == BINLOG_FORMAT_ROW' failed in THD::is_current_stmt_binlog_format_row

Store old value of binlog format before wsrep code so that
if we bail out because wsrep is not ready for connections
we can restore binlog format correctly.

Adding any unknown option to the "[mysqld_safe]" section makes
mysqld impossible to start with mysqld_multi. For example, after
adding the unknown option "numa_interleave" to the "[mysqld_safe]"
section, mysqld_multi exits with the following diagnostics:

[ERROR] /usr/local/mysql/bin/mysqld: unknown option '--numa_interleave'

To get rid of this behavior, this patch adds the passing of the default
group suffix from mysqld_multi to the mysqld_safe side.

Change the default timestamping URL, again
http://timestamp.globalsign.com/?signature=sha2 seems to work fine atm

connection.

Ignore harmless X509_R_CERT_ALREADY_IN_HASH_TABLE, similar to how Curl or
other projects treat it.

Keyvalue can be longer than REC_VERSION_56_MAX_INDEX_COL_LEN
and this leads out-of-array reference. Use dynamic memory
allocation using actual max length of key value.

Online log for insert operation of redundant table fails with
index->is_instant() assert. Purge can reset the n_core_fields when
alter is waiting to upgrade MDL for commit phase of DDL. In the
meantime, any insert DML tries to log the operation fails with
index is not being instant.

row_log_get_n_core_fields(): Get the n_core_fields of online log
for the given index.

rec_get_converted_size_comp_prefix_low(): Use n_core_fields of online
log when InnoDB calculates the size of data tuple during redundant
row format table rebuild.

rec_convert_dtuple_to_rec_comp(): Use n_core_fields of online log
when InnoDB does the conversion of data tuple to record during
redudant row format table rebuild.

- Adding the test case which has more than 129 instant columns.

The query causing the issue here has implicit grouping for we
have to produce one row with special values for the aggregates
(depending on each aggregate function), and NULL values for all
non-aggregate fields.

The subselect item where implicit grouping was being done,
null_value for the subselect item was not being set for
the case when the implicit grouping produces NULL values
for the items in the select list of the subquery.
This which was leading to the crash.

The fix would be to set the null_value when all the values
for the row column have NULL values.

Further changes are

1) etting null_value for Item_singlerow_subselect only
   after val_* functions have been called.
2) Introduced a parameter null_value_inside to Item_cache that
   would store be set to TRUE if any of the arguments of the
   Item_cache are null.

Reviewed And co-authored by Monty

- This is caused by merge commit a26e7a37.
InnoDB fails to fetch the next index field when there is a externally
stored column length check involved.

MDEV-25105 (commit 7a4fbb55)
in MariaDB 10.6 will refuse the innodb_checksum_algorithm
values none, innodb, strict_none, strict_innodb.

We will issue a deprecation warning if innodb_checksum_algorithm
is set to any of these non-default unsafe values.

innodb_checksum_algorithm=crc32 was made the default in
MySQL 5.7 and MariaDB Server 10.2, and given that older versions
of the server have reached their end of life, there is no valid
reason to use anything else than innodb_checksum_algorithm=crc32
or innodb_checksum_algorithm=strict_crc32 in MariaDB 10.3.

Reviewed by: Sergei Golubchik

This bug manifested itself when executing queries with multiple reference
to a CTE specified by a query expression with union and having its
column names explicitly declared. In this case the server returned a bogus
error message about unknown column name. It happened because while for the
first reference to the CTE the names of the columns returned by the CTE
specification were properly changed to match the CTE definition for the
other references it was not done. This was a consequence  of not quite
complete code of the function With_element::clone_parsed_spec() that forgot
to set the reference to the CTE definition for unit structures representing
non-first CTE references.

Approved by dmitry.shulga@mariadb.com

This bug could affect multi-way join queries with embedded outer joins that
contained a conjunctive IS NULL predicate over a non-nullable column from
inner table of an outer join. The predicate could occur in WHERE condition
or in ON condition. Due to this bug a wrong result set could be returned by
the query. The bug manifested itself only when join buffers were employed
for join operations.

The problem appeared because
- a bug in the function JOIN_CACHE::get_match_flag_by_pos that not always
  returned proper match flags for embedding outer joins stored together
  with table rows put a join buffer.
- bug in the function JOIN_CACHE::join_matching_records that not always
  correctly determined that a row from the buffer could be skipped due
  to applied 'not_exists' optimization.
Example:
  SELECT * FROM t1 LEFT JOIN ((t2 LEFT JOIN t3 ON c = d) JOIN t4) ON b = e
    WHERE e IS NULL;

The patch introduces a new function that finds the match flag for a record
from join buffer specifying the buffer where this flag has to be found.
The function is called JOIN_CACHE::get_match_flag_by_pos_from_join_buffer().
Now this function rather than JOIN_CACHE::get_match_flag_by_pos() is used
in JOIN_CACHE::skip_if_matched() to check whether a record from the join
buffer must be ignored when extending the record by null complements.
Also the code of the function JOIN_CACHE::skip_if_not_needed_match() has
been changed. The function checks whether a record from the join buffer
still may produce some useful extensions.
Also some clarifying comments has been added.

Approved by monty@mariadb.com.

It was possibile for a user to create an interlocked state which may go on
for a significant period of time. There is a tight loop in the FTWRL code
path that tries to repeatedly acquire a read lock. As the weight of FTWRL
lock is the smallest among others, it's always selected by the deadlock
detector, but can never be killed.

Imaging the following sequence:

    connection_0                 connection_1

 GET_LOCK("l1", 0);
                             LOCK TABLES t WRITE;
 FLUSH TABLES WITH READ LOCK;
                             GET_LOCK("l1", 1000);

The GET_LOCK statement in connection_1 triggers the deadlock detector,
which tries to select the lock in FTWRL, since its weight is 0. However,
since a loop in Global_read_lock::lock_global_read_lock() tries to always
win, it tries to acquire lock again. Which invokes the deadlock detector,
and that cycle continues until GET_LOCK in connection_1 times out.

This patch resolves the live-locking by introducing a dynamic bonus to the
deadlock weight associated with every lock. Each lock gets a bonus weight
each time it's selected by the deadlock detector. In case of a live-lock
situation, those locks that cannot be killed, get additional weight each
iteration. Eventually their weight becomes so high that the deadlock
detector shifts its attention to other lock, until it find the one that
can be killed.

InnoDB set the space in dict_table_t as NULL when table
is discarded. So InnoDB shouldn't use the space present
in table to detect whether the given tablespace is
temporary tablespace.

btr_node_ptr_max_size(): Let us remove the debug assertion that was
added in MDEV-14637. The assertion assumed that no additional
indexes exist in mysql.innodb_index_stats or mysql.innodb_table_stats.
The code path is working around an incorrect definition of a table,
interpreting VARCHAR(64) as the more correct VARCHAR(199).

No test case will be added, because MDEV-24579 proves that executing
DDL on the statistics tables involves a race condition. The test
case included the following:

	ALTER TABLE mysql.innodb_index_stats ADD KEY (stat_name);
	CREATE TABLE t (a INT) ENGINE=InnoDB STATS_PERSISTENT=1;

		failed in dtuple_convert_big_rec

In dtuple_convert_big_rec(), InnoDB fails to consider the
instant metadata blob while choosing the variable length
field.

implements in a native way get_exepath which gives reliably the full
path.

A bogus error message was issued for any outer references occurred in
ON expressions used in subqueries. This prevented execution of queries
containing subqueries as soon as they used outer references in their ON
clauses. This happened because the Name_resolution_context structure
created for any ON expression erroneously had the field outer_context set
to NULL. The fields select_lex of this structure was not set correctly
either.

The idea of the fix was taken from mysql code of the function
push_new_name_resolution_context().

Approved by dmitry.shulga@mariadb.com

MDEV-24868 Server crashes in optimize_schema_tables_memory_usage after select from information_schema.innodb_sys_columns

optimize_schema_tables_memory_usage() crashed when its argument included
TABLE struct that was not fully initialized.

To prevent such a crash, we check if a table is an information schema table at
the beginning of each iteration.

Closes #1768